# Mark Bietz

> Mark Bietz is a marketing and ecommerce executive best known for helping build HalloweenCostumes.com and FUN.com into one of the largest online costume and pop-culture merchandise retailers in the world. As Chief Marketing Officer of the Mankato, Minnesota-based company, he led digital growth that scaled revenue roughly 10x-20x, championing data-driven email personalization and short-form video. A self-described curious operator who learned the business from brand to CRM to operations, he now also works as a fractional CMO and advisor to venture-backed and private-equity-backed brands, and speaks widely on modern ecommerce and the rise of agentic commerce.

- **Role:** Chief Marketing Officer at FUN.com / HalloweenCostumes.com; Fractional CMO and advisor
- **Organizations:** FUN.com, HalloweenCostumes.com, KittyPooClub.com, Google Performance Advertising Council, Minnesota State University, Mankato - College of Business Advisory Board
- **Nationality:** American
- **Education:** Minnesota State University, Mankato
- **Known for:** Helped grow HalloweenCostumes.com / FUN.com into one of the largest online-only costume and pop-culture retailers in the world., Led digital marketing that scaled company revenue roughly 10x-20x during his tenure (figures cited range from $15M to $140M-$200M+)., Drove 10-15% email conversion lifts through purchase- and cart-based personalization.

## Career timeline

- **2001-2007** — Attended Minnesota State University, Mankato; started an internet marketing agency while in college.
- **2016** — Became Chief Marketing Officer at FUN.com after earlier roles as VP of Product and VP of Marketing.
- **2020** — FUN.com / HalloweenCostumes.com posts record revenue during a pandemic-era Halloween season.
- **2023** — Leads a major expansion into short-form video and customer-generated content across the brand's sites and social channels.
- **2024** — Takes on fractional CMO work, including for D2C subscription brand KittyPooClub.com, while advising venture- and PE-backed brands.
- **2026** — Speaks at ADWEEK House: POSSIBLE on modern ecommerce and agentic commerce.

## Achievements

- Helped grow HalloweenCostumes.com / FUN.com into one of the largest online-only costume and pop-culture retailers in the world.
- Led digital marketing that scaled company revenue roughly 10x-20x during his tenure (figures cited range from $15M to $140M-$200M+).
- Drove 10-15% email conversion lifts through purchase- and cart-based personalization.
- Expanded the brand's short-form video program, sparking a wave of customer-generated content.
- Serves on the Google Performance Advertising Council.
- Advisory Board member for Minnesota State University's College of Business.

## Latest updates

- **2026-07** — Listed as a speaker for ADWEEK House: POSSIBLE 2026, presenting on modern ecommerce and agentic commerce.
- **2024-06** — Profiled as a fractional CMO working with D2C subscription brand KittyPooClub.com and advising growth-stage brands.

## Links

- Website: https://fun.com
- LinkedIn: http://www.linkedin.com/in/markbietz
- Twitter/X: https://twitter.com/FunDotCom_
- Facebook: https://www.facebook.com/fundotcom

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Profile page: https://yespress.io/mark-bietz
Published by YesPress — https://yespress.io
Last updated: 2026-07-25